Hi Kari,
There are several things you should consider before making a decision about which park to visit on which day. Make a list of things you want to do in order of importance. Ask every member of your party so that everyone can be part of the planing & make sure everyone gets to do some of their "must dos". Also need to consider your budget for your trip.
If dining at any of the table service restaurants is a must do, make your ADRs as soon as your 180 day window of opportunity opens by calling 407-WDW-DINE. Decide if there are any special things you want to do like the Pirates & Pals Fireworks Voyage or Cirque du Soleil & check availability. Decide which parades & nighttime entertainment at the parks you want to see & check the calendar as some are not scheduled every evening - especially Fantasmic!
Then check the on-line calendars for park hours. If you are staying on property, look for EMHs on the schedules too. August calendars are now available on-line. Click
here for MK,
here for Epcot,
here for DHS &
here for AK. From there click on a specific day for a schedule of parades & fireworks keeping in mind that the calendar is always subject to change.
Once you have your research complete, you can then make your decision as to which parks to visit on which days. MK is always my 1st recommendation because it is how it all started.
Also keep in mind that it is going to be super hot in August so you may want to take a break during the day & head back to your room for a break. Plan a couple of days off to take a break from the parks. Wishing you magical memories!